Oh yes I just tried it and noticed no change in tire wear to previous levels. I edited my own database with the values given in both the 25 and 50% just to be sure, hopefully its just a matter of editing another set of variables? But thanks for the effort all the same!

I simply found 25% of 24.29 on the calculator, then added that to the original value, so for example;

25% of 24.29 = 6.0725, *I then added 6.07 to 24.29 (remember, two decimal places only) which returned 30.36 for the Supersoft tyres. To keep it safe I then used the same method for increase for each tyre type so there is still uniform behaviour in-game.

You'll notice the wet tyre's carry the same values for Medium and Hard. +25% increase distance is equivalent of *gaining* 1.5 laps per every 6 laps on the *super soft tires.